Brake for hoisting-machines



2 Q N I H S U NU N (No Model.)

BRAKE FOB HUNTING MACHINES.

Patented Dec. 27, 1887.

2 Shets-Sheet 2.

(No Model.)

N. B. CUSHI'NG.

BRAKE POE HOISTI-NG MACHINES.

when

wk I @AANAAN eff UNITED STATES PATENT OFFICE! NICHOLS B. CUSHING, OF JERSEY CITY, NEW JERSEY.

BRAKE FOR HOlSTlNG-MACHINES.

SPECIFICATION forming part of Letters Patent No. 375,343, dated December 27, 1887.

Application filed December 31, 1886. Serial No. 223,151. (N 0 model.)

To all whom. it may concern.-

Be it known that I, Nrorrors B. GUsHINe, of Jersey City, in the State of New Jersey, have invented a new and useful Improvement in Brakes for Hoisting-lllachines, of which the following is a specification.

My invention relates to machines used for hoisting and lowering weights, either merchandisc or passengers, with or without the use of a platform or car; and the object of my invention is to provide such machines with a device by which the machine can be automatically stopped in'the event of certain con tingencies. These contingencies are liable to occur in the running of the machine, and unless the machine is stopped there is danger of loss of life or merchandise, or the breaking of the machine. The contingencies to which I refer are as follows: In lowering a weight, car 20 or platform it is liable to become obstructed or hung up in its ways, in which case, if the machine continues its motion, the hoist-ropes are unwound and no longer support the weight, and if the obstruction gives way the weight will fall, there being no tension on the hoistrope. The hand-rope sometimes becomes fouled, in which case some part of the mechanism must give way unless the machine is stopped. My invention is intended to stop the machine automatically in the event of either of these contingencies occurring, or in case the hoist-ropes should break. I attain this object by means of the device shown in the accompanying drawings.

Figure 1 is a plan. Fig. 2 is a side elevation, and Fig. 3 an elevation of the pulley end of an ordinary winding and hoisting machine containing my invention. Fig. 4 is an enlarged view of the hand-rope wheel. Fig. 5 is adetailed drawing of the shaft and arms, with the supporting-pin actuatedby them. Fig. 6 is an enlarged plan of the end of the regulator-lever, showing the projections engaged upon the center-pin of the toggle which supports the brake-lever.

A is the frame-work of the machine; B, the winding-drum; B, B and B, the gears and pinions which connect the winding-drum with the belt-pulleys E.

O is the hoist-rope.

D is the brake-band, which is tightened round the brake-wheel D by the action. of the j usted that when the machine exceeds a given rate of speed the action of the regulator depresses the lever H. p

The foregoing are all well-known and com; monly used parts in hoisting and winding machines.

J is a rod forked at one end, and between the forks it carries a loose sheave or roller, K, adj usted to press against the hoist-rope C. The rod J is long enough to pass through the entire length of the machine, and at the end opposite the sheave it passes through a hearing, J which is pivoted to the frame of the machine, so that the rod J is free to swing upon J as a center, to allow the sheave K to follow the hoist-rope as it is wound or unwound on the drum B. The rod J is provided with a collar, J which takes the thrust of aspiral spring, L, strung upon the rod J, and by the endlong pressure of which the sheave is kept in a state of pressure against the hoist-rope O, by the tension of which the sheave K is held in place.

R is the brake-lever, which is weigh ted, and

if left free would fall and tighten the brake' band D upon the brake-wheel D and stop the machine. For its ordinary operations the machineis stopped and started by means of abelt, U, operating the beltpulleys E, the belt being shifted to the desired belt-pulley by means of the belt-shifting bar F. The brake-wheel D must then be free from the pressure of the brake-band D, which is intended to operate only in certain contingencies, as will be hereinafter explained.

To prevent the brake-lever R from operating and tightening the brake-band D, it must be supported in position out of operation. In practice it is supported by means of the toggle S. The upper link of the toggle S is pivoted ICO to the, brake-lever B. The pin S, Fig. 6, which holds together the links of the toggle S, is confined between two projections, Hand H, Fig. 6, upon the regulator-lever H, which prevents the toggle from closing or doubling up. As commonly used, the lower joint of the toggle is pivoted to the frame of the machine, and so the toggle is held sufficiently rigid to support the brake-lever R out of operation.

In my invention I hold thelower joint of the toggle by a pin, (shown in detail at M in Fig. 5,) which is moved in or out of a hollow bracket, M (shown in section in Fig. 5,) and which is firmly attached to the frame of the machine. XVhcn the point of the pin ll is thrust out of the hollow bracket M it enters the lower joint of the toggle T and supports it; but when withdrawn in the hollow bracket M by the action of the arm M, the toggle S is no longer supported and falls, and with it the brakelever It, which applies the brake, and the machine is stopped. The pin M is provided with an opening or slot to take the point of the arm M and the hollow bracket M has an elongated slot, (indicated in the section, Fig. 5,) through which the arm M passes to operate the pin ll M is a shaft supported in hearings in an upright position in the frame of the machine, carrying two arms, one, M at the top, and one, M, at the lower end, fixed to the shaft in a position at right angles to each other. The point of the lower arm, M, operates the pin M, as I have before explained, thrusting it out from the hollow bracket M to support the toggle S, and to withdraw it to let the toggle fall and apply the brake. The upper arm, M, of the shaft BI is pivoted to the end of a link, M, the other end of which is pivoted to a collar, J, on the sheave-rod J.

The operation of this part of my in vention is as follows: In case the hoist-rope O breaks or becomes slack, the spring Ii, pressing upon the collar J 2 on the sheave-rod J, thrusts the sheaverod forward, it no longer being held bythe tension of the hoist-rope O, and by the action of the link M and the arm M" the shaft M is rotated, carrying the arm M with it, and by the action of the arm M the pin M is withdrawn in the hollow bracket M and the toggle S, being no longer supported byits lower link, falls, and with it the brake-lever R, and the brake is applied, as before explained, and the machine stopped.

The machine, as previously mentioned, is provided with a regulator, G, which is constructed and operated substantially like the governor of a steam-engine, and is adjusted to a given rate of speed. This is connected in the usual and customary manner with one end of the regulator-beam II, which swings upon a central pivot attached to the frame of the machine. The other end of the regulatorbeam II carries two projections. (Shown enlarged at H and H Fig. 6.) The middle pin, S of the toggle-joint S is loosely confined by the project-ions II and H and by this means the toggleS is prevented from falling together or doubling up. In case the rate of speed of the machine becomes excessive and exceeds the rate to which the regulator G is adjusted, a condition in which there is danger, by the well-known law of the operation of the regulator G it depresses that end of the regulatorbeam H which is connected with the regulator, the other en d ofthe regulator-beam His raised, releasing the middle pin, S, of the toggle S, which toggle then falls together and no longer supports the brake-levcr'lt, which falls and applies the brake and stops the machine, as before explained. This is an old and wellknown device in winding and hoisting ma: chines of the class shown, and I have inserted it in my drawings and described it in these specifications only for the purpose of explaining the operation of the toggle-joint S in supporting the brake-lever R.

For the ordinary operations of the machine it is started, stopped, and reversed by means of hand-ropes, which are led into the elevatorshaft, or to such place as may be convenient for the operator. The hand-ropes pass around and operate the hand-rope wheel N, which is carried by a shaft, N, j ournaled to the frame of the machine. The shaft N carries a long pinion, N", Fig. 4., which gears into a rack upon the belt-shifting bar F, and by means of which the belt is shifted from one pulley, I], to another to reverse the motion, or to the loose pulley E to stop the machine. The customary and usual method is to attach the handrope wheel N to its shaft N. Instead of attaching it I construct my hand-rope wheel N, as shown in detail in Fig. 4, to run loose on the shaft N, and I provide the shaft N with a fixed collar, N". The free end of the shaft N projects beyond the hand-rope wheel N and is screw threaded and provided with a nut and washer and a spiral spring, N, and by means of the nut and washer and spring N the hand-rope wheel N is thrust and firmly held against the collar N, the boss of the hand rope wheel N being held in close contact with the fixed collar N". For the ordinary operation of the machine the friction between the boss of the hand-rope wheel N and the collar- N" must be such that the hand-rope wheel N will not turn upon the shaft N, but will actuate it, and the pinion N upon it, so that the machine can be stopped, started, or reversed by the hand-rope acting upon the hand rope wheel N. If, now, the hand-rope wheel N should become caught or obstructed and prevented from turning by any cause-as, for example, by the hand-ropes becoming fouledand the limiting device (shown at O I, and to be hereinafter explained) should be called upon to actuate the belt-shifting bar F, the force thereby exerted by the rack carried by the belt-shifting bar F upon the pinion N would overcome the friction between the boss of the hand-rope wheel N and the collar N, and the shaft N would rotate within the handrope wheel N, and the belt wouldbe shifted.

It is for the purpose of creating just so much friction as will enable the hand-rope wheel N to actuate the shaft N and pinion N for the ordinary operations of the machine that the nut, washer, and spring N are provided, the contact being adjusted to provide j ust so much friction as would be necessary for such operation, but not enough to prevent the shaft N from turning within the hand-rope wheel N, should an extraordinary force be brought to bear upon the pinion N", through the action of the belt-shifting bar F, or the rack upon the bar 0 of the limiting device.

The limiting device before mentioned, which has long been known and used in machines of the class shown by the drawings, is

- intended to limit the travel of the car or platform, being adjusted to operate the belt-shifting bar F when the. car or platform has reached its highest and its lowest limit of travel. The

shaft of the winding-drum B is extended be-- yond the frame of the machine and is threaded with a screw. At the end of the screwed part nearest the frame of the machine it carries a ratchet, into the teeth of which are fitted to engage the teeth of a similar ratchet upon the end of apinion, P. The pinion P is tapped and works on the screw on the shaft of the winding-drum, and carries a similar ratchet on its outer side, which is fitted to engage with a ratchet on a collar, 1?,near the outer end of the screw. The bar 0 carries a rack on its under side, which engages with the pinion I side engage with the ratchet upon either the shaft or the collar 1?, as the case may be, and the bar 0 is thrust in the direction of its length, and the rack upon its end, by means of the pinion on the shaft N, operates the beltshifting bar F and stops the machine. The amount of travel to be allowed the pinion P on the screwedsh'aft is determined by the number of turns of thewinding-drnm necessary to raise and lower the car or platform to its highest and lowest points, and the collar 1 is made fast at the point so determined, so that the ratchet on one side of the pinion P will come into gear with the corresponding ratchet and shift the belt to the loose pulley and stop the machine when the car or platform is at its lowest point of travel, and the same operation will be performed by the ratchet on the other side of the pinion when the car or platform has reached the highest point of its travel.

It is obvious that if the shaft N of the handrope wheel N should be rigidly attached to the hand-rope wheel and the hand-rope wheel be prevented from turning by the hand-ropes becoming fouled, or from any cause whatever, the pinion 1? and the bar 0 would not be able to perform their functions of stopping the machine, but some part of the machine would give way and be injured. This is a not infrequent accident; but with my hand-rope wheel in such a contingency the friction between the collar'N and the boss of the hand-rope wheel N would be overcome, and the shaft N would rot-ate within the hand-rope wheel and the belt be shifted and the machine stopped, as I have before explained.

As my invention can be applied to existing hoisting-machines of various construction, I do not limit myself to the specific construction of the details of my invention as shown in my drawings; but the shape and conformation thereof can be modified to perform the functions which I have explained.

What I claim as my invention, and to secure by Letters Patent, is-

1. In a winding and hoisting machine, a hand-rope wheel adapted to have longitudinal desire and rotary motion on its shaft, in combinationwith a frictioncollar rigidly attached to the shaft, and a compression-spring for forcing the handrope wheel against the friction-collar, all operating substantiallyas set forth.

2. In a winding and hoisting machine, the hollow bracket M in combination with the toggle S, the supporting-pin M, the arms M and M the shaft M, the link M the sheave rod J, the brakestrap D, and the brake-lever R, substantially .as described.

3. In a winding or hoisting machine, the combination of the hand-rope wheel N, the shaft N, the pinion N the belt-shifting bar F, the limiting-bar O, and the pinion 1?, substantially as described, and for the purpose specified. 4. In a winding or hoisting machine, the combination and arrangement of the sheaverod J the shaft M, and the arms M and M the pin M, and the link M the hollow bracket M the toggle S, the brake strap D, the brakelever It, the belt-shifting bar F, and the handrope wheel N, substantially as described, and for the purpose specified.

NICHOLS n. OUSHING.

Witnesses:

A. Q. .GARRETSON, M. T. ROSENBERG.

ICC 

